In the field of high performance computing, living body simulation is performed to numerically analyze a phenomenon that occurs in an organ, such as a heart. For example, simulation using a computer, such as a supercomputer, reproduces the behavior of cardiac muscle and displays the behavior of a heart using a three dimensional computer graphics technology. Also, simulation is also performed for coronary circulation associated with the behavior of the cardiac muscle.
The coronary circulation is a vascular network (hereinafter, referred to as “coronary circulation network”) that supplies blood to cardiac muscle of a heart. The coronary circulation network for supplying blood to cardiac muscle includes a coronary artery for transporting blood from a Valsalva sinus, and a coronary vein for transporting carbon dioxide that is ejected from the cardiac muscle that has consumed oxygen. The coronary circulation network ranges from a blood vessel having a diameter confirmable as an organ to a blood vessel having a diameter for circulating blood into cardiac muscle. The research for anatomically figuring out the entire structure of the vascular network is proceeding. For example, there is a literature relevant to hemodynamic analysis of coronary capillary.
If coronary circulation is simulated using a three-dimensional model corresponding to a heart of a patient, a patient-specific coronary circulation is reproduced by a computer. Thus, the technology for creating a three-dimensional model specific to a patient is being studied. For example, there is a study on the technology for creating a three-dimensional model representing at least a part of a patient's heart, on the basis of patient-specific data relevant to the geometry of the patient's heart. Also, there is a study on the technology for generating a 3D model of a heart and cardiac blood vessels, using the data generated from a plurality of tomographic images of a body including a heart. Further, there is also a study on the technology for calculating the motion of a three dimensional shape, using pictures of a moving object, such as a heart, which is taken from a plurality of directions.
Note that, if coronary circulation including a narrow vascular network is simulated, the processing load of a computer becomes very large. Thus, the technology for efficiently simulating coronary circulation including a narrow vascular network is being studied.
See, for example, International Publication Pamphlet No. WO 2012/021307, Japanese Laid-open Patent Publication Nos. 2011-200549, 2004-201730, and 2013-233369. Also, see Ghassan S. Kassab et al., “A hemodynamic analysis of coronary capillary blood flow based on anatomic and distensibility data”, American Journal of Physiology—Heart and Circulatory Physiology, 1 Dec. 1999, Vol. 277 No. 6 H2158-H2166.
In order to observe a simulation result of a heart using a three-dimensional model, the simulation result is displayed on the three-dimensional model. For example, the simulation result is observed on a three-dimensional model by displaying the three-dimensional model in such a manner that a difference between values of physical quantities of cardiac muscle and blood vessel estimated by the simulation is replaced by a difference between colors.
However, the vascular network of the microcirculatory system is defined only in a two-dimensional flat structure, and the simulation result of the microcirculatory system is unable to be confirmed on a three-dimensional structure. That is, from the view point of simulation of blood flow such as coronary circulation, a sufficiently accurate simulation result is obtained with respect to the microcirculatory system including narrow blood vessels, such as blood capillary, without creating a three dimensional model. Hence, with respect to the microcirculatory system, the model of the vascular network used in the simulation defines a structure, such as a diameter, a length, and a connection relationship, of blood vessels on a two-dimensional plane, and does not define a three-dimensional structure. As a result, a three-dimensional structure of the microcirculatory system is not reproduced, and a simulation result of the microcirculatory system is unable to be observed on a three-dimensional structure.